transliteration

use Drupal\Core\Language\LanguageInterface;
 
$transliterated = \Drupal::transliteration()->transliterate($string, LanguageInterface::LANGCODE_DEFAULT, '_');
$transliterated = mb_strtolower($transliterated);
$transliterated = preg_replace('@[^a-z0-9_]+@', '_', $transliterated);